Turbulent and transition pipe flow of dilute aqueous polymer solutions
Turbulent and transition pipe flow of dilute aqueous polymer solutions
复制标题
稀聚合物水溶液的湍流和过渡管流
DOI：
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发表时间：
1969
期刊：
影响因子：
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通讯作者：
D. Kreid
中科院分区：
文献类型：
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作者：
R. Goldstein;R. Adrian;D. Kreid
向水中添加微量的高分子量聚合物可以大大降低湍流管流摩擦。本文用激光多普勒局部速度测量仪研究了50 WPPM聚氧乙烯水溶液在14 mm直径管道中心的转捩和湍流流动。在研究的雷诺数范围内，向水中加入聚合物不会显著改变中心线处的纵向湍流强度水平。聚合物添加的令人惊讶的结果发生在低于2，500的雷诺数的驼峰区域中。在这个区域中的频谱的相对带宽的增加意味着流体速度的不确定性。这一结果，连同观察到的中心线与体积速度之比相对于纯水同时降低，表明在添加Polyox WSR 301后，流动不再是稳定的Poietille型。频谱中没有尖峰进一步意味着流动不是间歇性的，因为层流和湍流段塞交替通过测量点。在这些雷诺数下，流动可能是层流但不稳定的。(18参考文献）«少
The addition of minute quantities of high molecular weight polymers to water can produce a large reduction in the turbulent pipe flow friction. A laser-Doppler instrument for measuring local velocity is used to study transition and turbulent pipe flow of a 50-WPPM aqueous solution of Polyox WSR 301 (polyethylene oxide) at the center of a 14-mm diam pipe. The addition of the polymer to water does not significantly alter the level of the longitudinal turbulence intensity at the center line over the range of Reynolds numbers studied. A surprising result of polymer addition occurs below a Reynolds number of 2,500 in the region of the hump. The increased relative band widths of the frequency spectra in this region imply an uncertainty in the fluid velocity. This result, together with the observed concurrent decrease in the ratio of center line to bulk velocity relative to pure water, shows that the flow is no longer of the steady Poiseuille type after the addition of Polyox WSR 301. The absence of spikes from the frequency spectra further implies that the flow is not intermittent in the sense that laminar and turbulent slugs are alternately passing the point of measurement. At these Reynolds numbers,more » the flow is probably laminar but unsteady. (18 refs.)« less